I would like to make a few comments here:
CA law has 2 different classes of "Assault Weapons" and possession of an Unregistered Assault Weapon or the possession of a Registered Assault Weapon but you are not the owner that it is registered to constitutes a FELONY under the Law.
Assault Weapons in the first class (are those weapons which are listed by Name on the 1989 Roberti Roos Assault Weapons Ban). The Registration deadline for these weapons passed back in 1990.
Now here is a VERY important point about the 1989 Roberti Roos Act..( this law defines what is an Assault Weapon by NAME) under this law the State Attorney General has the power to ADD a weapon to the list. (Don't even think about a court challenge: The CA State Supreme Court has ruled that it is NOT a violation of the Seperation of Powers for an Attorney General to add weapons to the list.)
Weapons on this LIST do NOT need to have any distinguishing characteristics, just have the name on the receiver which matches the name on the list.
So if you have a pre ban FAL which says something like: Fabrique Nationale FAL..it would be a Category 1 Rifle under the 1989 Roberti Roos Act and as such would have had been registered prior to 1990..
However if you have a "FAL" that says..."Imbel" on the Receiver and is marked Century Arms Sporter..and has a thumbhole stock and no flash hider it would be considered to an Category 3 Assault Weapon and would fall under SB23 in which case it would be defined by the number of distinguishing characteristics, and would have had been registered prior to Jan.1 2001.
IF however, you REMOVE the Thumbhole stock then..it would no longer be defined as an Assault Weapon and thus you could legally bring it into California.
A combined listing of Category 1 and 2 Assault Weapons (as defined under the Roberti Roos Act) can be found at:
http://caag.state.ca.us/firearms/forms/pdf/awguide.pdf
see pages 92,93,94
Assault Weapons in the Second Class fall under SB23 which defined what an "Assault Weapon" is by having a certain number of characteristics (or features). For example..a Semi Automatic Rifle which is capable of accepting a detachable magazine which has a Flash hider and/or a Pistol Grip and/or a Thumbhole Stock is defined as an "Assault Weapon"
(ie. if you have an M1A with a Flash Hider and standard stock it is an "Assault Weapon" however if you remove Flash hider and had a muzzle break on it instead then it would no longer be defined as an SB23 Assault Weapon.)
At the same time CA legislators (in their "wisdom") outlawed all registration after Jan 1.,2001. (Sales and Transfers were stopped on Jan 1, 2000) for weapons.
On the issue of "high capacity" magazines, since you have not been a resident of CA since Jan.1, 2000...it is easy for the authorities to prove that you broke the law..(assuming you break it by moving here with hi cap magazines)
Basically my advice to you is to STAY AWAY from California!
There is more gun control legislation coming up here in California..
notably a Ban on 50 caliber centerfire rifles AND a law requiring Ballistic Identification of Firearms.
BTW on Assault Weapons: in California the DOJ database containing the list of registered owners and their Assault Weapons is linked to the DMV database containing their driver's licenses and vehicle registrations. So when a police officer runs a check on your vehicle's registration and license, he is automatically flagged if you are a registered owner of a registered assault weapon.
It is highly advisable for registered California owners when driving with an Assault Weapon in the car in California to carry some photo copied proof of their registration of the particular Assault Weapon that they have in their car.
Otherwise, they might face an arrest and get their weapon confiscated...and they might not get the weapon returned even if it is determined that they are the lawful owner. Because the SB23 law contains a clause that the local District Attorney can deem an Assault Weapon to be a "public nuisance" and have it permanently confiscated.
(yes..in California AW owners and their weapons are registered just like a sex offender, the act of registering an Assault Weapon and the linkage of the two databases caused a registration of people, just like being a Jew in Pre WWII Nazi Germany)
I find this particularly irksome, since the DMV handles both licenses and California ID cards...everytime I move the databases get updated on my location.
Being an Inmate here in the California Gulag..my best advice is
DON'T MOVE HERE!!!!